Telephone-exchange system



Oct. 12, 1926. 1,602,809

w. w. CARPENTER TELEPHONE EXCHANGE SYSTEM Filed Nov. 14, 1924 2 Sheets-Sheet 1 lnvenfan" I Warren It flame/12%;

w. w. CARPENTER mswruounnxcumes SYSTEM Filed Nov. 14, 1924 2 Sheets-Sheet 2 Warren 11. Kama/2f Patented Oct. 12, 1926.

UNITED STATES PATENT OFFICE.

WARREN W. CARPENTER. OF QUEENS VILLAGE, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW NEW YORK.

YORK, N. Y.. A CORPORATION OF TELEPHON E-EXOHAN GE SYSTEM.

Application filed November [14, 1924. Serial No. 749,850.

This invention relates to telephone ex change systems, and more particularly to telephone systems wherein automatic switches and automatic switch controlling 6 apparatus are employed for connecting subscribers lines for purposes of conversation.

In telephone systems where idle interconnecting trunks are selected under the supervision of common controlling mechanisms, the condition sometimes arises under which two selective switches may be operated simultaneously or quite nearly so to seize the same idle trunk. In such an instance, the particular switch which possesses the more rapid operating characteristics will obviously be successful in seizing the trunk.

However, when there is an appreciable interval between the initiation of the testing operation and the subsequent operation of a switch to seize this trunk, there may exist a condition in which the trunk has been tested for and found idle and during the interval elapsing before the operation of the selective switch to seize this trunk, a second selective switch may attempt to seize the same trunk.

It is an object of the invention, therefore, to render a trunk, which appears before a number of switches possessing; different operating characteristics, nonselectable during the period subsequent to the recording of an idle condition of said trunk and prior to the operation of said switch to seize the trunk.

A feature of the invention relates-to a common registering mechanism which records the idle condition of any one of a number of trunks, together with the novel means for nullifying said record when said trunk has been seized subsequent to the recording of its idle condition.

A still further feature resides in the means for multipling trunks before switches of different types. v

Another feature of the invention relates to a telephone system I wherein different types of switches are employed in completing connections wherein each trunk of a group is selectable by a switch of any type, and wherein each of said trunks has individual means normally effective to maintain different selectable conditions thereon, and operatively effective tomaintain the same non-selectable potential on said trunk at the switches of all types, before which said trunk appears.

Other features and advantages of the invention will become apparent when the following detailed description and the appended claims have been considered.

Referring to the drawing Fig. 1 shows a plurality of subscribers lines and a number of selective switches for interconnecting these lines. This figure also illustrates diagrammatically a sender selector, a registering and controlling sender, together with a number of multi-contact relay connecting devices.

F ig. 2 shows a portion of the testing and controlling equipment in the marker which is associable with any sender and with certain of the switches shown in Fig. 1 for-controlling the operation thereof.

Fig. 1 when positioned above Fig. 2 shows a sufficient portion of a telephone exchange system, and in sutlicient detail to enable an understanding to be attained of a preferred form of carrying out the invention.

The invention has been shown as applied to a telephone system employing switches of the coordinate type as well as switches of the power driven type. The coordinate selector switches 100, 150, 160 and 170 and the sender selector 110 may be of the same general construction and mode of operation as that disclosed in the British patent to the Western Electric Company, 183,438, accepted Sept. 6, 1923 and in the application of S. B. Williams, Serial No. 596,179, filed Oct. 23, 1922, whereas the switches 151, 152, 153 and 15-1 are preferably of the general character of those disclosed in the patent to A. E. Lundell, No. 1,168,819, issued Jan. 18, 1.916. The sender 110, sender connector 130, frame connector 140 and trunk connector 180 are similar in construction and method of operation to corresponding elements in the copending application of Varren 1V. Carpenter, Serial No. 703,362, filed April 1, 192 1. Inasmuch as the present invention is concerned mainly with the manner of testing for, and'rendering nonselectable an interconnecting trunk, a detailed operation of the switching and controlling apparatus is not deemed necessary.

An examination of Fig. 1 of the drawing will reveal the fact that certain of the trunks extendingbetween the coordinate Limited, No.v

switches 150 and 160 are also multipled before the power-driven switches 152 and 153. Two of these trunks, namely trunks 161 and 166 are shown n'iultipled, it being understood that other trunks as 158, 159 etc. have an app'carance not only in switch 150 but also in switch 152.

Detailed dose rip tion.

It will be assumed that the subscriber at station 101 has initiated a call by the removal of his receiver from the switchhook. The removal of the receiver results in the automatic operation of line switch 100 whereby an idle trunk as 155 is seized, and sender selector switch 110 is also actuated to associa e an idle register sender as 120 with the calling line. The calling subscriber thereupon dials the designation of the wanted line which results in the positioning of the several registers in sender 120. li hen the reg isters have been thus set, the sender connector 130 is actuated to associate an idle marker or switch controlling mechanism partially shown in Fig. 2 with the sender. As soon as the marker has been thus associated start relay 201 is energized, and the numerical record is transferred from the reg isters of sender 110 to corresponding registers 250 in the marker. Upon the comple tion of the transferring of the record from the sender to the marker the frame connector 1 10 and the trunk connector 180 are selectively actuated. The frame connector 1&0 associates the links of switch 150, in which trunk 155 terminates, with the marker testing mechanism shown in Fig. 2. The trunk connector 180 also associates the test conductors of the trunks in the desired group outgoing from switch 150 with the same testing mechanism. At this time also the vertical operating magnets 156 and 157 are actuated. F or a detailed description of the manner in which the foregoing operations are effected, reference may be had to the application of "Warren W. Carpenter, hereinbefore referred to.

The marker is now in readiness to test the links in switch 150 as well as the trunks in the desired group which, for the purposes of description. ma be assumed to include trunks 158, 159, 161, etc. Vi ith trunk vertical magnet 157 operated a circuit is completed from ground at the lower armature and contact thereof, thence by means of the frame connector 1 10 to battery through the winding of relay 202. Bela 202 relates to the vertical row of contacts 111 in switch 150 and serves an indication to the marker that a district trunk vertical magnet has operated. T e test relays 240 are now connected to the various links and trunks in switch 150, and an appreciable interval is provided to allow these test relays to take their complete set ting in accordance with the busy or idle condition of the links and trunks. When any of the trunks 108, 159, 161 etc. are idle, the relay 116, 11.7, 118, etc. individual thereto is normal. Consequently battery is connected through a right-hand non-inductive wind ing 14-1, 1 12, etc., back contact of the normal relay, to the sleeve conductor of the idle trunk appearing in switch 152. The presence of this battery potential upon the sleeve conductor of the trunk identi lies the same, in the well-known manner, as selectable by switch 152; whereas the absence of ground on the sleeve conductor identities the trunk as idle to switch 150 as will hereinafter appear. Should any of the trunks 158, 159, etc. be seized by the operation of switch 150 the sleeve conductor is immediately grounded causing the actuation of the corresponding relay as 116 by means of the left hand winding. The actuation of this relay extends the ground potential through its front cont-act, thereby reducing the potential on the sleeve conductor of the trunk at switch 152 and identifying this trunk as non-selectable. Should, however, trunk 162 be seized by switch 152, then in the well known manner a relay as 157 operates and grounds sleeve conductor 168 thus identifying trunk 162 as non-selectable to other switches similar to switch 152 before which trunk 1652 is multipled. Tn this case relay 117 is normal and the non-selectable potential is not connected to the sleeve conductor of trunk 162 at switch 150. However, this trunk cannot be seized by switch 150 as Will be explained hereinafter.

It will be assumed that link 112 is busy, and the remaining links are idle. It will also be assumed that trunk 158 is busy at switch 150, and trunk 159 is busy at switch 152, while the remaining trunks are idle. Accordingly relay 116 is operated, while relay 117 is normal and a circuit may be traced from battery through the right winding of test relay 20 1, right outer armature and back contact of relay 208, conductor 251, contacts of frame connector 1 10, left winding of magnet 123, thence to the grounded sleeve conductor of busy link 112. The resistance of the right-hand winding of relay 204; is of such a value as to prevent the energization of magnet 123 when included in series with the left winding thereof. Another circuit may be traced through the left winding of relay 201, left armature and back contact of relay 208, conductor 252, contacts of trunk connector 180, right armature and front contact of relay 116 to the grounded sleeve conductor of trunk 158. It will be noted that the energization of either one or both windings of the test relays 2-10 is sufiicient to cause actuation of the same. Therefore, when relay 20% operates it closes a locking circuit which is completed through the left winding and the right contacts of to. relay 157. Relay the said relay to ground at the left contacts of relay 201. As a result of the busy conditionof trunk 159 at switch 152, the test relay 205 is energized in a circuit traceable from battery through the left winding of relay 205, left back contacts of relay 209', conductor 258, contacts of connector 180 to sleeve conductor 164 of trunk 159 which is grounded by the operation of a relay similar 205 operates and locks, thus rendering trunk 159 non-selectable by switch 150. Since link 114 and trunk 161 have both been assumed to be idle, the corresponding relay 206 remains normal. Accordingly, when the test relays 240 have be come stabilized, a circuit is completed from battery, through the winding of relay 210, left contacts of relay 206, left armatures and front contacts of relays 205, and 204 in so ries, conductor 254, contacts of frame connector 140, conductor 253, contacts of relay 202 to ground at the right contacts of rela' 201. Should a trunk as 166 be seized by switch 152 after its idle condition has been recorded on relays 240 and prior to the stabilization of these relays, the record is immediately revised by means of ground through the armature of sleeve relay 5?, thence through contacts of connector 180 to cause the operation of the corresponding test relay 207. The operation of relay 210 completes a circuit from ground through the winding of the common relay 212, the left armature and front contact of relay 210, conductor 256, contacts of trunks connector 180, armature and back contact and noninductive winding 14?) of relay 118 to battery. Relay 212 operates in this circuit. The resistance of relay 212 is suliiciently low to reduce the potential on conductor 165, rendering trunk 161 non-selectable at switch 152. A. circuit is now completed for energizing the horizontal operating magnet 121 which may be traced from battery through the right winding thereof, contacts of frame connector 140, conductor 255, right outer armature and front contact of relay 210, to ground at the contacts of relay 212. Magnet 121 is energized in this circuit but an interval elapses before connection is completed between trunk 155 and trunk 161 by means of link 114. During the interval while mag:- net 121 is operating trunk161 is rendered non-selectable at switch 152, by the reduced potential caused bv relay 212 on conductor 165 as above described.

It will be noted that when trunk 155 was seized by switch 100, relay 122 was actuated in the manner described in detail in the above mentioned application of 1V. W. Carpenter. lVith magnet 121 completely operated a circuitis completed for initiating the release of the marker and for setting certain of the contacts in switch 150. This circuit may be traced from ground at the contacts of relay 122, contacts of switch 150,

tobatterythrough the operating winding of relay 118. Relay 118 operates in this cir cult and extends the same ground through its armature and front contact to the sleeve conductor 165 of trunk 161, appearing before the power driven switch 152. Trunk 161 is thus rendered non-selectable at both the coordinate switch 150 and the power driven switch 152, and remains nonselectable after the disconnection of relay 212. The above traced ground is also extended by means of contacts of connector 180, conductor 257, right inner armature and contact of relay 210, contacts of relay 216, to battery through the winding of relay 215. Relay 215, in turn, closes obvious operating circuits for relays 213 and 214 in parallel. In the manner described in detail in the above mentioned application of 1V. Carpenter, the operation of relays 213 and 214 brings about the release of the mark r, the sender connector 130, frame connector 140 and trunk connector 180 as well as the release of verti al magnets 156 and 157. The connection through switch 150 however is maintained by the continued energization of mag net 121 which is held through both of its windings in series to the grounded conductor of trunk 161.

The calling line having thus been extended to the trunk 161, the incoming switch 160 and the final switch 170 are ated under the control of ignation as recorded in selectively actuthe called line ties the sender to connect with the called subscribefs line. The

manner in which the sender controls the op-- eration of the incoming and final switches is completely described in the copending application of 1V. V. Carpenter hereinbefore referred to.

What is claimed is:

1.111 a telephone system, calling lines. automatic switches for extending said calling lines, trunks, each trunk appearing in a plurality of said switches, means for identifying a non-selectable trunk in the same manner at each of said plurality of switches, means for operating one of said plurality of switches to seize a trunk and place a non-- selectable condition thereon at said plural.- ity of switches, means responsive to the operation of another of said plurality of svitches to seize a trunk and place a non selectable condition thereon at said other of said switches alone, and means for preventing the seizure of a trunk which is in a nonselect-able condition at one of said switches and in a selectable condition at the other of said switches.

' 2. In a telephone system, calling lines, automatic switches for extending said lines, trunks, each trunk appearing before a plurality of said switches, means for identity ing 'a selectable trunk at each of said plu- Lee it switches said means being india trunk and common to said pluit switches, means for identifying a non-sel ctable tank in the same manner at each 0 said plurality of switches, means for operating one of said switches to place a non-selectable condition on a trunk at said plu'ality of switches, means responsive to the operation of another of said switches to place a non-selectable condition on said trunk at said other switch alone, and means for yn'eventingthe seizure of a trnnlr which is in a selectable condition at said one of said switches and in a non-selectable con lition at said other of said switches,

in a telephone system, calling lines, automatic switches of ditl erent types for e:rtending said lines, trunks, each trunk ap pearing before diiierent types of switches, means "for identifying a non-selectable trunk in the same manner at the different type switches before which it appears, means for operating a switch of one type to seize a trunk and place a nonselectable condition thereon at another type switch beiore which said trnnlr appears, means for operating said other type of switch to seize said trunk and place a non-selectable condi ion thereon at said othr type of switch alone, and means for preventing the seizure of a trnnl: which is in a nonselectable condition at no of said switches and in a selectable condition at another of said switches of a dillerent type.

In a telephone system, callin G D 2 7 toinatic switches oi diherent types tor extending; said once, trunks, each trunl-r appearing before differenttypes of switches, means for identitying a selectable trunk at ""arent types or switches, said in ans s1 id o being individual to a trunk and common to said diii erent types of switches, means for identifying a non-selectable trunk in the same manner at said different types of switches, means for operating a SWlQCll 01": one type to place a non-selectable condition on a trunk at switch oi another type, means responsive to the operation of a switch oft said other type to place a non-selectable condition on a trunk at said switch of said other ype alone, and means for pre enting t ie seizure of a trunk which is in a selectable condition at a switca oi one type and in a non-selectable condition at a switch oi another type.

5. In a telephone system, calling lines, an antoin tic switch of the progressively movable type and Eli automatic switch of the coordinate type both of said switches being adapted to extend said line" a trunk appearing before both of said swi ches, means for identifying a non-selcctable trunk in the same manner at each of said switches, means for op rating said coordinate switch to seize said t lil'ili and to place thereon a non-selectable condition at both of said switches, means responsive to the operation of said progressively movable switch to seize Said trunk and to place thereon a non-selectable condition at said progressively movable switch alone.

6. in a telephone system, calling lines, an a itcmatic switch of one type, an automatic switch of a second type both of said switches being adapted to extend said lines, a group of trunks each trunk appearing before a switch or each of said types, a testing and controlling mechanism associable with said first n entioned switch, means in said mechanism for peiiorming a sinmltaneous test of all trunks in said group to set up a record of he condition oi said trunks, n'ieans reto the completion of said setting ting; said first mentioned switch to tifdnli, means responsive to the id idle trunk by said second mench for causing said setting to be d means for causing said first itch to seize an idle trunk ce with said revised setting.

a 7. In a t-leghone system, calling lines, a PI'OQYGSS'LVClf movable LUtOlillltlC switch, a

i coordinate auton'iatic switch, a trunk accessible in common to both of said switches, a relay individual to said trunk normally eti ective to maintain the test conductor of said trunk at different potentials at each of said switches, means responsive to the seizure of said trunk by said coordinate switch for operating said relay to maintain the same busy potential. on said truin: at both oi said switches, and means responsive to the seizure of said trunk by said progressively movable switch for maintaining said busy potential on said rank at said progressively movable switch alone.

In witness whereof, I hereunto subscribe my name this (3th day of November A. D., 1924;.

lVi'iBREN n. CARPENTER 

